1. Field of the Invention
The present invention relates to a high frequency semiconductor apparatus, transmitting apparatus and receiving apparatus, and an art applied to, for instance, an antenna-integrated wireless communication apparatus for microwave communication having an antenna function.
2. Description of the Related Art
In recent years, as the processing speed of a data processing apparatus and the resolution of an image processing apparatus have increased, a high-speed and large-capacity personal communication using a high frequency wave such as a microwave has attracted public attention. Since there is higher power loss at a connecting portion of an antenna and a high frequency circuit especially in a millimeter-wave band, it has been attempted to develop an antenna-integrated wireless communication apparatus having the antenna and the high frequency circuit integrated (for instance, refer to Japanese Unexamined Patent Publication JP-A 8-250913 (1996) (page 5, FIG. 10)).
FIG. 9 is a cross sectional view showing a conventional high frequency semiconductor apparatus. The antenna-integrated wireless communication apparatus comprises a base 4 having dielectric layers 1 and 2 and a ground layer 3 which is sandwiched between the dielectric layers 1 and 2. The ground layer 3 is provided with a slot portion 4a. A planar antenna 6 is formed on one surface of a package 5 facing outside. A feeding microstrip line 7 is formed on one surface of the dielectric layer 1 facing an internal space of the package. The feeding microstrip lines 7 are electrically connected to an output terminal 9 and input terminal 10 of a monolithic microwave integrated circuit 8 (abbreviated to MMIC) with a bonding wire 11.
A conventional high frequency transmission line as typified by a microstrip has a width of only several hundred of micrometers (μm) since characteristic impedance of the conventional high frequency transmission line is 50 Ω. In the above-described antenna-integrated wireless communication apparatus, heat generated by the MMIC must be radiated by the feeding microstrip line 7 which is narrow in width and connected to the MMIC. Therefore, it is not possible to sufficiently radiate the heat generated by a high frequency semiconductor element such as the MMIC, and the heat is confined to a space closed by a lid 12. As a result, the high frequency semiconductor element operates in a high temperature caused by the heat generated by the high frequency semiconductor element itself, which leads a bungle or deterioration of characteristics.